I think that animals come back as wood knots!
(OK, so not really, but these pictures are really cool)
So now you are going to have to put on your warped PIE imagination...I know it is stretching here...but just try.
Here is an OWL:
Here is an Ostrich...the big knots are the eyes...and its beak etc... or if you look at the big knots as ears, it could be a mouse that has an unfortunate facial defect of a misplaced eye...
Here is a Horse with a go-go- gadget eye...
here is my Dragon Fly: